Fine Metal Mask (FMM for short) is a common key component in a liquid crystal display manufacturing process, for example, it is often used in an evaporation process. In the evaporation process, accurate alignment between the FMM and a substrate (glass) should be ensured, otherwise position accuracy of a pattern to be manufactured will be adversely affected. Therefore, it needs to ensure position accuracy of the FMM in for example net machine or stretching equipment, so as to ensure accurate alignment between the FMM and the substrate.